A porcine model of chronic hepatitis E virus (HEV) infection identifies male reproductive glands as sites of viral persistence

Hepatitis E virus (HEV) is an expanding zoonotic viral disease threat. Although HEV causes acute viral hepatitis, it is increasingly being recognized as a systemic pathogen with detection and damage in extrahepatic tissues. The presence of HEV RNA in the semen of chronically infected human patients in the absence of viremia and fecal shedding and presence of HEV in the sperm head underscores the need to understand the interaction of HEV within the male reproduction system. The role of male accessory glands in the dissemination and persistence of HEV infection has not been studied. Using an immunosuppressed pig model for chronic HEV infection, we demonstrate infectious HEV in mature sperm cells, altering the sperm motility and morphology. HEV isolated from sperm cells remained infectious in human hepatoma cells. Spermatic fluid contained lower virus titers than the sperm cells from chronically infected pigs, highlighting that the sperm cells themselves can associate with the virus. Evaluation of the male accessory glands demonstrated viral replication, infiltration of CD45 leukocytes, and apoptosis associated with HEV infection. A decrease in serum testosterone levels was evident in the HEV-infected pigs. Even though a lower viral RNA titer was seen in serum and feces of chronically infected, immunosuppressed, and ribavirin-treated pigs, high viral RNA and infectious particles in sperm is a concern. Our findings necessitate further studies defining the mechanism of sperm cell invasion by HEV and the risk of sexual transmission of HEV during both acute and chronic phases of infection.